In German patent 23 06 755 there is described a crystal bar or crucible holder for devices for crucibleless zone melting and for crystal drawn from a crucible, utilizing magnetic principles and in which a magnetizable core is suspended from a magnet which may be referred to herein as an axial stabilizing magnet since its function is to fix the core axially with respect to this magnet or coil, the device being then axially shifted.
The means for displacing the melt along the growth axis generally comprises entraining electromagnets located outside the zone-melting chamber.
During the axial displacement, therefore, the ferromagnetic core slides along the melt chamber wall so that vibration or chattering resulting from the frictional contact of the core with this wall may result and give rise to spontaneous defects in the crystal growth. Because of the contact of the wall of the melting chamber with the core, external influences on the apparatus in the form of vibration or shocks also cannot be prevented from detrimentally affecting the crystal growth process.